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Firefox crashes on startup (even in safe mode)

  • 3 replies
  • 6 have this problem
  • 5 views
  • Last reply by cor-el

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Firefox just updated to 12 last night. Now it crashes every time I try to open it. I've tried in safe mode. That doesn't work either. maybe 1 in 20 times I try to start in safe mode, Visual Studio catches the exception, but Firefox opens until I dismiss the VS exception window. In that circumstance, I've been able to click all the checkboxes to reset all information, but this doesn't help.

Firefox just updated to 12 last night. Now it crashes every time I try to open it. I've tried in safe mode. That doesn't work either. maybe 1 in 20 times I try to start in safe mode, Visual Studio catches the exception, but Firefox opens until I dismiss the VS exception window. In that circumstance, I've been able to click all the checkboxes to reset all information, but this doesn't help.

All Replies (3)

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As you have provided a Crash ID I assume you have already found and read the tips and troubleshooting information in firefox crashes

If everything is up-to-date and you are getting startup crashes even in safe mode the problem may be something within the Firerfox profile . Please try creating and using a new profile.

If that fails try a clean re-install of Firefox. That involves deleting the Firefox program folder, but do NOT use any option from Windows, or Firefox, that mention removing personal settings, because that will destroy bookmarks and passwords.


I do not see much information of use in the report for your CrashID b763479b-dbba-4b01-8ca0-e4c952120509

  • Crash Signature: @0x715b9e59
    • CSignatureTool: No proper signature could be created because no good data for the crashing thread (24) was found

Please post back saying what you have tried and how you get on.


(Anyone else with crashes please read the linked articles and post your own question with your own crashID)

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... and, if Firefox still crashes after a clean re-install of Firefox and after creating a new Firefox profile, there are other suggestions here:

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What happens if you disable the Visual C debugger?